Clamping claw for an endless conveyer

ABSTRACT

A clamping claw assembly is secured to an endless transport device, such as a chain conveyor. A fixed clamping jaw is engaged by a movable clamping jaw to secure a product placed between the two. The movable clamping jaw is carried by a lever arm which is movable by an actuating lever. The actuating lever is biased by a tension spring between stable open and closed positions, through a dead center position. The movable clamping jaw is in a locked condition when it is in its closed position due to the force applied by the tension spring.

FIELD OF THE INVENTION

The present invention relates to a clamping claw for an endless conveyorsuch as a chain conveyor. A fixed clamping jaw and a movable clampingjaw are provided. The movable clamping jaw has closed and openedpositions on either side of a dead center position. A lever arm is usedto move the movable clamping jaw.

DESCRIPTION OF THE PRIOR ART

A prior art clamping claw for an endless conveyor is known from EP 0 386442 A2, wherein a first, fixed clamping jaw is arranged in an openposition, and in which a pivotably seated second clamping jaw can bemoved against the first clamping jaw. The pivotable clamping jaw isarranged on a first lever arm of a three-armed lever. An actuatingroller for actuating the clamping jaw in its open and closed position isseated on a second lever arm. A third lever arm is embodied as anelement of a device for introducing the clamping force, wherein thisdevice overcomes a dead center when the clamping jaw is actuated.

U.S. Pat. No. 3,055,480 describes an endless conveyor for paperproducts, wherein the paper products are held by means of automaticlocking between two clamping jaw. For opening, one of the clamping jawis directedly actuated by means of a lever.

SUMMARY OF THE INVENTION

The object of the present invention is based on providing a clampingclaw for an endless conveyor.

In accordance with the present invention, this object is attained byproviding a clamping claw for an endless conveyor, such as a chainconveyor. A first fixed clamping jaw and a second movable or adjustableclamping jaw are provided. A lever is used to bring the adjustable jawinto open and closed positions by overcoming a center position. A springis used to hold the adjustable jaw in its open and closed positions.

The advantages which can be attained by means of the present inventionreside, in particular, in that a clamping claw has been created with theuse of a few components, whose movable clamping jaw is maintained, afterpassing dead center, in two defined end positions by means of a springforce.

It is of particular advantage that in the closed position the movableclamping jaw applies automatic locking to the clamped printed product.In the clamped position, it is impossible to pull out, and therefore tolose, the printed product to be conveyed. It is furthermore possible todo without large spring forces because of the presence of theself-securing clamping jaws. This results in increased service life ofthe components of the clamping claw.

The clamping claw is designed without a housing. Each clamping claw hasa clamping claw bottom, which constitutes a stop for the products to bepicked up. This stop assures a gentle pick-up as well as an error-freedeposit of the product to be conveyed.

A simple construction which has a force gradient, and which is easy onthe components, is achieved in that an actuation force and/or theclamping force is additionally introduced into a lever supporting theclamping jaw.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention is represented in thedrawings and will be described in greater detail in what follows.

Shown are in

FIG. 1, a schematic representation of a lateral view of a clamping clawin the open position;

FIG. 2, a schematic representation of a lateral view of a clamping clawin the closed position; and in

FIG. 3, a schematic representation analogous to FIG. 2, but with asecond embodiment of the actuating lever.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A clamping claw 1 for an endless conveyor which, for example, isconnected downstream of a rotary printing press, and which may be achain conveyor, essentially consists of a fixed first clamping jaw 4,fastened by means of a support 3 on a chain link 2 of a traction meansof the chain conveyor, and of a movable second clamping jaw 6, whichworks together with the first fixed clamping jaw 4. The chain link 2 hasat least on both ends a roller 5, which rollers run in a chain guide,not specifically represented.

It is also possible to use cables, belts or toothed belts, for example,instead of a chain, as traction means.

The support 3 for the first clamping jaw 4 is designed to be L-shaped,for example. A short leg 7 of the support 3 extends at right angles inrespect to a longitudinal axis 9 of the chain link 2 and is connectedwith the chain link 2. A long leg 8 of the support 3 is arrangedparallel with the longitudinal axis 9 of the chain link 2. An outer freeend 11 of the long leg 8 is designed to be V-shaped and is connectedwith the first clamping jaw 4. A clamping jaw bottom 10 formed by thejuncture of long leg 8 and clamping jaw 4 has a radius r10. The radiusr10 is greater than a radius of a front edge 12 of an object, forexample a printed product 13, conveyed by means of the clamping claw 1as may be seen by referring to FIG. 2.

The support 3 has a bore 14 at the junction of support legs 7 and 8,which extends at right angles to the longitudinal axis 9 of the chainlink 2. A pivot shaft 16 of a lever 17 is arranged in this bore 14. Thelever 17 has a first lever arm 18, on which the adjustable, pivotableclamping jaw 6 is fastened, and into which the actuating forces areintroduced. For this purpose, the first lever arm 18 is provided, on itsextended free end with a roller 19 for actuating the lever 17. Lever 17also has a second lever arm 22 which is seen more clearly in FIGS. 2 and3. On its end, the second lever arm 22 has a bearing bolt 23, which isused as the point 24 of application of the force from an end attachmentor first of a tension spring 26 that functions as an energy storagedevice. On its other or second end, the tension spring 26 has anabutment 27, which is in operative connection with a bearing bolt 28located on the outer end 11 of the long leg 8 of the support 3.

The support 3, which is L-shaped in cross section, extends in theparallel direction in relation to the pivot shaft 16. The support 3 hasat least the width of a chain link 2. The first clamping jaw 4 locatedon the support 3 is wider, for example twice as wide, as the support 3.

The lever 17 can be arranged as two lever members carried on the ends ofthe pivot shaft 16 respectively on both sides of the support 3 andconnected by means of the second clamping jaw 6. Therefore two tensionsprings 26 have been employed, and each one of the two first lever arms18 supports a roller 19. The second clamping jaw 6 can be provided witha radius on its end acting against the inside of the first clamping jaw4. Undesirable impressions on the printed product 13 are prevented bymeans of this.

A distance a1 between the free end of the clamping jaw 6, i.e. thecontact zone between the printed product 13 and the pivot shaft 16 ofthe clamping jaw 6, preferably is slightly larger than the shortestdistance between the pivot shaft 16 and the inside surface of theclamping jaw 4. This distance a1 may be seen in FIG. 2.

The clamping jaw 6 is placed against the printed product 13 in such away that the printed product 13 is clamped between the two clamping jaws4, 6. In the closed position of the clamping jaw 6, automatic locking isapplied to the printed product 13. For this purpose, a straight line 33extending between the end of the clamping jaw 6; i.e. the point of thecontact zone formed by the printed product 13 and the clamping jaw 6,and the pivot shaft 16 of the clamping jaw 6, and a tangent line placedagainst a contact zone between the printed product 13 and the clampingjaw 4, form an opening angle α. In a simplifying way, this opening angleα will be identified as the opening angle which is enclosed by the twoclamping jaws 4, 6. This opening angle α, which is required forautomatic locking in a direction away from the clamping jaw bottom 10,is a function of the coefficient of friction between the clamping jaws4, 6 and the printed product 13 and is greater than 45°, preferably isgreater than 60° and is less than 90°. Therefore a printed product 13,which is held fast between the end of the second clamping jaw 6 and theinside of the first clamping jaw 4 cannot be pulled out.

The operation of the clamping claw 1, in accordance with the presentinvention is described in what follows:

The clamping claw 1 arranged on a chain link 2 of the chain conveyorinitially is in an open position A as shown in FIG. 1. At a loadingstation, for example at a paddle wheel of a folding apparatus, a printedproduct 13 is conducted between the clamping jaws 4, 6. As a result ofthe actuation of the first lever arm 18 in a clockwise direction ofrotation D, the bearing bolt 23 with the point 24 of application offorce from the spring 26 describes a circle around the pivot shaft 16.The radius of the circle corresponds to the length of the lever arm 22.In the process, the point 24 of application of force of the tensionspring 26 passes, from a stable position A below a dead center positionB, to a dead center position B. In the course of this, the tensionspring is tensed. The dead center position B is represented by astraight line 29 connecting the point 24 of application of force of thetension spring 26, the pivot shaft 16 of the lever 17, and the abutment27 of the tension spring 26. After passing through this dead centerposition B, the tension spring 26 contracts again. The free end of thesecond clamping jaw 6 comes to rest against the printed product 13 inthe closed position C which is shown in FIGS. 2 and 3.

The stable positions, which are in the open and closed positions A, C ofthe second clamping jaw 6, are achieved since distance between the point24 of the application of force and the abutment 27 of the tension spring26 in the open and closed positions are less than the length of thespring 26 in the dead center distance, i.e. of this distance in the deadcenter position. The clamping jaw 6 is therefore held in the open andclosed positions by the force storage device 26, i.e. without continuedforce applied by, for example, a cam control. The thickness of theprinted product 13 can be between 0.1 mm and several millimeters.

When the printed product 13 is to be released, the first lever arm 18 isactuated in a counterclockwise direction E as shown in FIG. 2. Afterpassing through the dead center position B, the second clamping jaw 6again takes up a stable position in the open position A.

In accordance with a second preferred embodiment, a further roller 31 isassigned to the first lever arm 18 of a lever 32, which lever 32 isanalogous to lever 17. This second roller 31 is arranged between thefirst roller 19 and the clamping jaw 6.

The arrangement of a second roller 31 in addition to the roller 19 isadvantageous due to the fact that switching of the second clamping jaw 6into the end positions A, C can be performed by means of differentrollers 19, 31.

In place of the lever 17, 32 having two lever arms, it is possible toprovide only a single lever arm. The adjustable clamping jaw 6 isfastened on this single lever arm, and the fastening forces for movingthe clamping jaw 6 into its open and closed position as well as theclamping forces are introduced there.

While preferred embodiments of a clamping claw for an endless conveyorin accordance with the present invention have been set forth fully andcompletely hereinabove, it will be apparent to one of skill in the artthat a number of changes in, for example the type of printing pressbeing used, the type of folder used, and the like may be made withoutdeparting from the true spirit and scope of the present invention whichis accordingly to be limited only by the following claims.

What is claimed is:
 1. A clamping claw for an endless conveyor comprising: a support secured to the endless conveyor, said support including a first end secured to said endless conveyor, and a second end; a first, fixed clamping jaw supported adjacent said second end of said support; a second, movable clamping jaw cooperating with said first, fixed clamping jaw; a pivotable lever carried by said support adjacent said first end of said support, said pivotable lever having a first lever arm and a second lever arm said second lever arm being pivotable about a pivot shaft passing through said support, said first lever arm being attached to said second, movable clamping jaw, said second lever arm being pivotable on said pivot shaft to move said second movable clamping jaw between an open position, an intermediate center position, and a closed position with respect to said first fixed clamping jaw; and A force storage device having a first end secured to said second lever arm and having a second end secured to said second end of said support said first and second ends of said force storage device being located at first and second opposite sides of said pivot shaft, said force storage device generating an actuating force for moving said second, movable clamping jaw between said open and closed positions and for generating a clamping force on said second, movable clamping jaw in said closed position of said second movable clamping jaw, said second, movable clamping jaw being locked in said closed position by said force storage device moving past said center position.
 2. The clamping claw of claim 1 wherein said fixed clamping jaw and said movable clamping jaw enclose an opening angle of greater than 45° in said closed position.
 3. The clamping claw of claim 1 wherein said first, fixed clamping jaw and said support define a generally v-shaped clamping jaw bottom extending transverse to a longitudinal direction of the endless conveyor, said v-shaped clamping jaw bottom forming a stop for products received by said clamping claw. 